Hydraulic brake coupling



M y 2 4 VAN DEREN 2,202,070

HYDRAULIC BRAKE COUPLING Original Filed July 6, 1937 2 Sheets-Sheet 1 L20 Y M4 @525 IN VENTOR.

ATTORNEY.

May 28, 1940. VAN DEREN HYDRAULIC BRAKE COUPLING Original Filed July 6,1937 2 Sheets-Sheet 2 Awa Mm/DEMA/ INVENTOR Patented May 28, 1940 UNITEDSTATES PATENT OFFICE Application July 6, 1937, Serial No. 152,043Renewed November 10, 1939 7 Claims. (Cl. 188-3) My invention relates toimprovements in braking mechanism for use in simultaneously actuatingthe brakes of a motor vehicle and a trailer connected thereto. Theinvention is hereinafter described and illustrated in several of itsmost preferred forms.

One important object of the invention resides in the employment ofimproved means for hydraulically operating the brakes of a trailer in munison with the brakes of the vehicle to which it is attached, thebraking force and length of brake pedal movement required to operate thebrakes remaining substantially constant whether the trailer is attachedor not.

Another object of the invention resides in improved means formaintaining a braking system free from leaks.

A further object resides in the improvement of a coupling for joiningvehicles permitting tandem attaching and detaching without loss ofbraking pressure in the line.

A further object of the invention resides in the provision of improvedmechanism for joining and operating separate systems of hydraulic brakemechanisms without the flow of fluid from one to the other system.

Still another object pertains to an improved means for regulating theproportional amount of the braking force which is transmitted to thebrakes of the trailer. Still other objects, ad-

vantages and features of invention will hereinafter appear.

In the structure of the preferred and alternative embodiments shown inthe drawings- Fig. 1 is a plan view showing the improvement mounted onthe rear end of a motor driven vehicle to which the draw-bar of atrailer is attached.

Fig. 2 is a section taken on line 22 of Fig. 1. 40 Fig. 3 is a partlongitudinal side elevation and part vertical mid-section of the devicewith the means for actuating the brakes of the trailer shown removed.

Fig. 4 is a diagrammatic showing of the brak- 45 ing mechanism oftractor and trailer.

Fig. 5 is a modification of the structure shown in Fig. 2.

Fig. 6 is a part longitudinal side elevation and part verticalmid-section of the structure shown 50 in Fig. 5 with the means foractuating the brakes of the trailer removed.

Fig. 7 is a modification of the mounting of the cylinders shown in Fig.1.

Fig. 8 is a section taken on line 88 of Fig. 7. Fig. 9 is a partlongitudinal side elevation and part vertical mid-section of thecylinders shown in Fig. 7. I

Referring in detail to the drawings, and at first more particularly toFigs. 1 and 4, the master or pressure supply cylinder is connected bymeans .5 of a main conduit 20 andbranch conduits 2],

22 and 23 with the four brake operating cylinders 2, 3, 4 and 5 actuatedby the pressure produced in said cylinder l by the piston la thereinoperated by the brake pedal 6, said pedal being mounted 1,0 in aconventional manner upon the vehicle frame 24 shown in part in Fig. l,towhich the trailer is attached by means of the drawbar 25 and yoke 26.

By means of the novel coupling device "I, brake operating pressure iscreated in the brake cylinders 8 and 9 of the trailer thru the operationof the pedal 6, said coupling device 1 being in communication With saidcylinders 8 and 9 through a conduit 28 and its branches 29.

Said coupling device 7 is shownmounted upon 20 a platform or bracket 30carried by the yoke 26 of the frame 24 of thetrailing vehicle. Said deyVice l comprises a fixed cylindrical casing ll having fitted Within it apiston head 52 furnished with a rod l3, this piston operating within apis- 25 ton chamber 3| bounded at one end by a head 32 and at itsopposite end by a cross Wall 33 thru which the rod l3 has a working fit.The conduit 20 supplies operating pressure to the outer face of thepiston head l2 through the cylinder 30 head 32.

The cylindrical coupling device 1 also includes a detachable,cylindrical section 50 having within it a piston chamber l5 within whichoperates a piston head 16 furnished with a piston rod 35. 35 Said pistonchamber I5 is closed at its outer end by a head 36 thru which leads theconduit 28 which supplies the trailer brake cylinders 8 and 9. At itsopposite or inner end said chamber I5 is closed by a partition or crosswall 3'! which has a tubular, central projection 38 thru which the rod35 has a working fit.

The cylindrical sections H and M of the coupling device l, respectivelyhave cavitated or cylindrically recessed end portions 40 and 4!, each ofthese, in the assembled device, forming a closure for the otherwise openmouth of the other. These two sections, when assembled, are respectivelyfurnished with abutting flanges 02 and 43 clamped together by cap screws45. When the 0 section It is secured to the section II by means of saidcap screws the piston rods l3 and 35 are brought into alinement witheach other, permitting the former rod to act in an endwise manner uponthe latter. From the view pointoi opera- 5&

tion, the piston having the rod i3 may be termed the primary piston andthe piston against which it abuts to operate the trailer brakes thesecondary piston.

When the trailer is detached from the front vehicle the cap screws areremoved, this permitting the coupling section i i to be detached.Thereupon a closure disk 55, having peripheral screw holes and acompression spring 45 secured to one of its faces, is secured to theflange 52 by means of the screws 5 3a. A cover is thus provided for therecess id and at the same time the spring 26 is utilized to engage theouter end of the piston rod l3 and to offer an opposition to its outwardmovement which will substantially compensate for the force required tooperate the brakes of the trailer when the section i l of the coupler lis attached. The cover 65 is shown having a tubular extension 359: tohouse the spring 46 said extension having an internally flanged mouthportion m against which the spring impelled follower plate may abut.

One advantage resulting from the provision of the closure plate 45 andthe spring carried thereby is that this arrangement accustoms the driverto a certain pedal touch and prevents him from being deceived, by aninequality of resistance to the pressure of his foot upon the brakepedal, as to how much foot pressure should be applied.

In the modification shown in Figs. 5 to 9, many of the parts aresubstantially the same as those already described and are thereforenumbered the same. Among these duplicated parts are the cylinder i Ihaving the outer head 32, chamber 3i, internal cross wall and recessedend portion the mouth of which is surrounded by the apertured flange d2to receive bolts or cap screws a l. But in place of the piston head 52of Fig. 2 there is shown in Fig. 5 a head or follower 58 secured to theinner end of a modified piston rod iii.

A Sylphon bellows 52 occupies and substantially fills said chamber 31,said bellows having a fiat end portion 55 which engages and actuates thefollower 58 together with the piston rod 5!. At its opposite end bellows52 has a tubular extension 56 which takes the place of the conduit ofFig. 2 and affords a pressure supply connection for said bellows to thecylinder of the pedal operable piston.

The rod M has a working fit thru the cross wall 33 and its projectingend portion opposes the piston rod ill likewise working thru the head 58of the detachable cylinder 59, said rod having secured to it thefollower 68.

Within the cylinder 59 is a bellows 6i, substantially a duplicate of theother bellows and having a like tubular extension 62 which conveys thebrake-operating pressure to the points of use. Unlike the cylinder i lof Fig. 2, the cylinder of Fig. 5 has no recessed left end, but its head58 is directly bolted to a more deeply recessed portion 64 at the rightend of the cylinder ii of Fig. 5.

In Fig. 6 the secondary cylinder 58 of the coupling device has beendetached from the primary cylinder H thereof and been replaced by theclosure plate of Fig. 3.

In Fig. '7 the primary cylinder Ha is shown juxtaposed to the secondarycylinder I la in a parallel rather than an axial relation. In thisstructure the primary piston rod acts upon one end portion of atransmission lever iii (which is pivotally mounted at H at its midlengthupon the bracket 300.) thus causing the opposite end portion of saidlever acting upon the projecting end portion of piston rod 51a of thesecondary cylinder I la.

In Fig, '7 is also shown a means for regulating the amount of brakingforce which is supplied to the brakes of the trailer in proportion tothat which is furnished to the brakes of the trailing vehicle. With thisend in view, the elongated mounting plate 15 is shown having in each endportion a longitudinal slot '16 through which passes a clamping screwTi, these clamping screws being anchored in a base plate 78 secured tothe chassis C.

When said clamping screws T1 are loosened, the mounting plate may beadjusted in the direction of its length carrying with it the cylindersHC. and Ma together with their piston rods filo. and Ella. The effect ofthis adjustment is to vary the distance of the primary piston rods fromthe pivot H of the transmission lever 10 and thus to give to the primarypiston rod filo a greater or less effective amount of braking force tobe conveyed to a secondary braking system located, for example, on atrailer.

The mounting plate "i5 is furnished with an indicating pointer 8 whichcooperates with graduations 2 on the base plate 78 to enable theoperator to determine the proper adjustment.

The secondary piston cylinder Ma may be detached from the mounting plate75 when the trailer is not attached to the trailing vehicle.

The cylinders Ho and Ma may or may not be supplied with the bellowswhich have been described. Owing to the fact that the primary piston rodSic has a contacting rather than a connected relation to the lever Iii,said rod together with the head carrying it may readily be removed andthen replaced by the spring-carrying plate 45 (Figs. 3 and 6) for thepurpose already stated.

Fig. 9 is an enlarged side view of the primary piston cylinder I la ofFig. '7. When the trailer is detached, the head 35a may be removed andreplaced by the spring carrying cap 45 of Fig. 6.

In Fig. 8 are shown more clearly the pivotal attacl nents of the leverl0 and draw-bar 25.

It should be understood that the present disclosure is for the purposeof illustration only and that this invention includes all modificationsand equivalents which fall within the scope of the subject matterclaimed.

What is claimed is:

1. In a device of the kind described, a coupler comprising a primary anda secondary piston section detachably related to each other and eachhaving juxtaposed piston rods operatively related whereby the piston rodof said primary section acts upon that of the secondary section to applythe brakes of a trailer, one of said coupler sections having acup-shaped or cylindrically recessed end portion, and a plate attachableto the mouth of the recessed part as a substitute closure therefor whenthe secondary section is inoperative, said closure plate carrying aspring positioned to supply opposition to compensate for the forcerequired to actuate the brakes of the trailer.

2. The subject matter of claim 1 and, said closure plate being furnishedwith a tubular housing for said spring, said housing containing afollower against which said spring acts.

3. In a device of the kind described, a coupler consisting of a primaryand a secondary piston section detachably related to each other and eachhaving a piston rod, means to operatively relate said piston rods,whereby the piston rod of said primary section causes action of that ofthe secondary section to apply the brakes of a trailer, and a plateattachable to the mouth of said primary section as a substitute closuretherefor when the secondary section is detached, said closure platecarrying a spring positioned to supply to the primary piston oppositionto compensate for the force required to actuate the brakes of thetrailer.

l. In a device of the kind described, a coupler including a cylinder, apiston in said cylinder, a piston rod for said piston having a portionextendible beyond the end of said cylinder,'and closure means for theend of said cylinder to confine the end of said rod within the limits ofsaid cylinder, and yieldingly oppose its outward movement,

5. In a device of the kind described, a primary piston cylinder, asecondary piston cylinder, said cylinders being mounted in a juxtaposedparallel relation to each other and each of said cylinders having withinit a piston with a rod which projects from it in the same direction asits fellow, a transmission lever pivotally mounted at its mid-lengthportion with one of its end portions in a laterally contactable relationto one of said piston rods and its opposite end portion in a likecontactable relation to the other of said piston rods, means to supplypedal controlled operating pressure to said primary cylinder, a mountingplate upon which both of said piston cylinders are mounted, saidcylinders being spaced apart in the direction of the length of saidmounting plate, a support for said mount-' ing plate, and means toreleasably secure said mounting plate to said support in differentadjustments with relation to the length of said mounting plate therebyvarying the contact distances of said piston rods with said transmissionlever in relation to the pivotal mounting of said lever, a brakingsystem, and meansto transmit the piston-produced braking pressures fromsaid secondary cylinder to said braking system.

6. In a device of the kind described, a primary piston cylinder, asecondary piston cylinder, said cylinders being mounted in a juxtaposedparallel relation to each other and each of said cylinders having withinit a piston with a rod which projects from it in the same direction asits fellow, a transmission lever pivotally mounted at its midlengthportion with one of its end portions in a laterally contactable relationto one of said piston rods and its opposite end portion in a likecontactable relation to the other of said piston rods, means to supplypedal controlled operating pressure to said primary cylinder, means totransmit piston-produced braking pressures from said secondary cylinderto a secondary braking system, one of said cylinders having a cup-shapedor cylindrically recessed end portion, and a plate attachable to themouth or" said recessed part as. a substitute closure therefore whensaid secondary braking system is detached, said closure plate carrying aspring positioned to supply to the piston rod of its cylinder oppositionto compensate for the force required to actuate said secondary brakingsystem.

7. In a device of the kind described, a primary cylinder, a secondarycylinder, said cylinders being mounted in a juxtaposed parallel relationto each other and each of said cylinders having within it a piston witha rod which projects from it in the same direction as its fellow, atransmission lever pivotally mounted at its mid-length portion with oneof its end portions in a laterally contactable relation to one of saidpiston rods and its opposite end portion in a like contactable relationto the other of said piston rods, a primary brake system, means tosupply pedal controlled operating pressure to said primary brake systemwhereby to actuate said primary cylinder, a mounting plate upon whichboth of said cylinders are mounted, said cylinders being spaced apart inthe direction of the length of said mounting plate, a support for saidmounting plate, and means to releasably secure said mounting plate tosaid support in different adjusts ments with relation to the length ofsaid mounting plate thereby varying the contact distances of said pistonIOds with said transmission lever in relation to the pivotal mounting ofsaid lever, a secondary braking system, and means to transmit thepiston-produced braking pressures from said secondary cylinder to saidsecondary braking system.

LARRY VAN DER/EN.

